Our currently funded NIH U-54 SCCPRR Center has provided the foundation for a rich, interactive environment for the pursuit of and training in reproductive biology and medicine at Stanford University. It consists of an integrated group of investigators in the Department of Gynecology and Obstetrics and for this competitive renewal adds an investigator in Developmental Biology to comprise four projects, one pilot project, and three cores (Administrative Core, Molecular Biology and In Situ Hybridization Core, and Bioinformatics Core). The projects are designed to investigate molecular mechanisms governing reproductive processes in the ovary, endometrium, and testis, and to benefit specifically from interactions among investigators and cores. The central theme of the Center is gonadal and endometrial function in reproduction, with a focus on the human, thereby enhancing the long-term goal of translational research to clinical reproductive disorders, including infertility and poor pregnancy outcome. Projects I and III (Hsueh and Conti) interact, as they focus on early ovarian follicle development and on the role of mechanisms governing meiosis in the female gonad, respectively. Project II (Giudice) investigates auto/paracrine mechanisms in human implantation, primarily involving the IGF system. It interacts extensively with Project HI (Conti) from the perspective of signaling mechanisms and Project IV (Fuller) due to new findings in human endometrium of the Drosophila homologs important in cell-cell interactions. In this renewal, we welcome a new project (IV, Fuller) that focuses on early events in meiosis in the male gonad, using the Drosophila model. It interacts with Projects I-IH The pilot project (Tazuke) focuses on early germ cell development in the male gonad using the Drosophila model with a translation to the human. It interacts will all projects. The Center is highly enriched by the University environment with seminars, courses, conferences, and core facilities. Issues of female infertility and fertility are critical to the national agenda to improve women's health care. Male factors also contribute significantly to reproductive failure, and understanding their pathogenesis and treatment is very important. Our Center's goal is to investigate basic cellular and physiologic processes involved in normal reproductive function, laying the foundation to understand abnormal follicle development, spermatogenesis, and implantation, associated with polycystic ovarian syndrome, premature ovarian failure, male infertility, miscarriage and ectopic pregnancy. Advances in the Center are anticipated to lead to new diagnostic and therapeutic modalities for reproductive disorders.